Vapor pressurized hydrostatic drive

ABSTRACT

A hydrostatic drive system generally of the type wherein vapor is alternately directed into one of two reservoir tanks so that working fluid in that tank is forced out of the tank by pressure of the vapor and through a fluidic motor to generate a mechanical output before it returns to refill the other tank. When the first tank is substantially depleted, the vapor pressure is directed into the refilled tank so that fluid from that tank now flows through the motor to refill the first, now depleted, tank. In one embodiment, cyclic pressure generated by a vapor generator forces fluid cyclically through an AC fluid motor. In another embodiment, heat from the working fluid is employed to generate the vapor pressure and reduce the temperature of the working fluid passing through the motor. In a further embodiment, the fuel serves as the working fluid and the vapor from the refilling tank is combusted to provide heat to convert the fuel from its liquid to vapor state. In another embodiment, the combustion gases are combined with the vapor so that, when water is the working fluid, the water vapor in the combustion gases serves as make up working fluid. In a further embodiment, heat from working fluid on its way to the motor is transferred to other working fluid in a second system to drive a second motor. Further aspects of the invention are set forth below.

United States Patent McAlister [4 Mar. 14, 1972 [54] VAPOR PRESSURIZEDHYDROSTATIC DRIVE [72] Inventor: Roy E. McAlister, 5285 N. Red RockDrive, Phoenix, Ariz. 85018 [22] Filed: July 28, 1970 [21] Appl. No.:58,934

2,955,897 10/1960 Noe 3,100,965 8/1963 Blackburn ..60/51 PrimaryExaminer-Edgar W. Geoghegan Assistant ExaminerAllen M. OstragerAttorney-Cushman, Darby & Cushman {57] ABSTRACT A hydrostatic drivesystem generally of the type wherein vapor is alternately directed intoone of two reservoir tanks so that working fluid in that tank is forcedout of the tank by pressure of the vapor and through a fluidic motor togenerate a mechanical output before it returns to refill the other tank.When the first tank is substantially depleted, the vapor pressure isdirected into the refilled tank so that fluid from that tank now flowsthrough the motor to refill the first, now depleted, tank. 1n oneembodiment, cyclic pressure generated by a vapor generator forces fluidcyclically through an AC fluid motor. In another embodiment, heat fromthe working fluid is employed to generate the vapor pressure and reducethe temperature of the working fluid passing through the motor. In afurther embodiment, the fuel serves as the working fluid and the vaporfrom the refilling tank is combusted to provide heat to convert the fuelfrom its liquid to vapor state. In another embodiment, the combustiongases are combined with the vapor so that, when water is the workingfluid, the water vapor in the combustion gases serves as make up workingfluid. In a further embodiment, heat from working fluid on its way tothe motor is transferred to other working fluid in a second system todrive a second motor. Further aspects of the invention are set forthbelow.

9 Claims, 18 Drawing Figures PAIENTEBMAR 14 I972 SHEET 1 OF 9 INVENTOR yZMZ/S/Z'E ATTORNEY$ PAIENTEDMAR 14 m2 SHEET 3 BF 9 K INVENTOR 1/5405756M ATTORNEYS PATENTEDHAR 14 I972 SHEET h 0F 9 a 7 -..F;INVENTOR MATTORNEE PMENTEDHAR 14 972 3,648, 15 8 sum 5 OF 9 FUEL /5 ,5372 INVENTORF0) .5 fl/( 05756 3 mag lah 4 A I Y -'Ja a? ATTORNEYS PATENTEDHAR 141972 T 648 ,458

sum 7 BF 9 A AAA/\AAAAAA IN VEN TOR ATTORNEY PATENTEDHAR 14 I972 SHEET 8[)F 9 INVENTOR 4%141/5726 ATTORNEYS VAPOR PRESSURIZED HYDROSTATIC 'DRIVE BRIEF DESCRIPTION OF THE PRIOR ART AND SUMMARY OF THE INVENTION Theinvention relation to a vapor pressurized hydrostatic drive forconverting heat into mechanical motion.

Over the past few centuries, one of the continuing goals of technologyhas been the improvement of systems for converting energy in the form ofheat into mechanical motion. The widely employed conventional steamengine and internal combustion engine are the products of this continuedeffort. Neither of these engines is, however, completely satisfactory.Both are complicated heavy machines whose efficiency in accomplishingthe energy conversion is normally quite low. The internal combustionengine produces pollutants which .are both dangerous and obnoxious.

One promising heat conversion apparatus which has been developedincludes a tank containing a working fluid and a fluid motor operativelyconnected to the tank so that when heat is added to the system apressure is generated on the fluid in the tank which forces it out thetank and through the motor, thus generating a mechanical output. Asecond tank can be added to the system so that the fluid after passagethrough the motor can refill that tank. When the second tank is full,pressure can be generated on the fluid in that tank to forcefluid flowout of the second and through the motor to refill the first. Suchsystems are shown, for example, inPike U.S. Pat. Nos. 228,555 and Parish2,941,608.

The present invention relates to a number of embodiments basicallysimilar to such devices. In these embodiments, the basic engine isimproved to increase its efficiency and make it more satisfactory foruse as an energy conversion system.

Many other objects and purposes of the invention will become clear fromthe following detailed .description of the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a first embodiment of theinvention with a DC fluid motor,

FIG. 2 shows a further embodiment with an AC fluid motor,

FIG. 3 shows a device for injecting fluid as fine droplets into a steamgenerator,

FIG. 4 shows a further embodiment of the invention wherein the fluid tobe vaporized is drawn from the reservoir tank,

FIG. 5 shows a further embodiment of the invention in which a resonantcoupled acoustic pump is employed to inject the fluid into a steamgenerator as fine droplets,

FIG. 6 shows a reservoir tank having a thin walled steam quench forpreventing thermal shock to the reservoir walls,

FIG. 7 shows a further embodiment of the invention wherein the workingfluid is a fuel which is combusted to provide heat,

FIG. 8 shows yet another embodiment of the invention in which fluidtransmitted to the steam generator absorbs heat from the working fluidin the tank being refilled,

FIG. 9 shows a further embodiment of the invention in which a poroussteam storage bed absorbs heat from the working fluid in the tank beingrefilled,

FIG. 10 shows another embodiment of the invention wherein a portion ofthe heat in the working fluid is recovered and employed to generate amechanical output,

FIG. 11 shows another embodiment in which heat in the fluid on its wayto the fluid motor is transmitted to fluid leaving the fluid motor onits way to refill one of the reservoir tanks,

FIG. 12 shows another embodiment of the invention wherein a portion ofthe working fluid is evaporated from the heat exchanger to cool theworking fluid,

FIG. 13 shows another embodiment of the invention in which the workingfluid which is vaporized absorbs heat from the working fluid in the tankbeing refilled,

FIG. 14 shows a further embodiment whereby heat in the working fluid onits way to the fluid motor is transferred to working fluid in a secondsystem to cause vaporization of that second fluid and operation of asecond fluid motor,

FIG. 15 shows an embodiment of the inventionwherein two systems areconnectedtogether to a single shaft,

FIG. 16 shows an embodiment of the invention inwhich each reservoirincludes fluids separated by an impenneable barrier which is able tomove within the reservoir,

FIG. 17 shows :another embodiment of the invention in which the heatgenerated by fuel being combusted is employed togenerate vapor pressureto force the fuel through a fluid motor and into the combustion chamber,

FIG. 18 showsa modification of the embodiment of FIG. I?

in which the vapor pressure in the reservoir tank is generated byvaporizing a portion of the fuel in that tank.

DETAILED DESCRIPTION OF THE DRAWINGS Reference is now made to FIG. 1which illustrates a hydrostatic drive system 18 suitable for use with aDC fluid motor. In this embodiment, as in many of the other embodimentsof the invention, as discussed in detail below, vapor is altemativelydirected into one of the two reservoir tanks 20 and 22 so that theworking fluid in that tank is forced out of the tank by the pressure ofthe vapor, and through a conventional fluidic motor 38 to generate amechanical output before it returns to refill the other tank. When thefirst tank is substantially depleted, the vapor pressure is directedinto the refilled tank so that the fluid from that tank now flows againthrough motor 38 to refill the first, now depleted, tank.

In FIG. 1, a suitable reservoir 24 of a fluid such aswater is connectedto a conventional phase converter or boiler 26 which converts the fluidfrom a liquid to a vapor phase. This conversion maybe accomplished byburning a suitable fuel such as a hydrocarbon adjacent boiler 26 so thatthe generated heat changes the phase of at least a portion of the fluidin boiler 26. Any other suitable arrangement for generating the vaporwhich is employed to impart motion to the working fluid can be employed.The vapor pressure output of boiler 26 is directed to either reservoirtank 20 or tank 22 via master valve 28 which may be a conventionalsolenoid valve or any other suitable type of conventional mechanism. Asdepicted schematically in FIG. 1, valve 28 is operated by a suitablecontrol apparatus 30, which alternately causes valve 28 to direct thevapor pressure generated by boiler 26 to reservoir tanks 20 and 22.Control 30 may be mechanically or otherwise linked to the fluid motor 38so that the position of the valve 28 is responsive to the physicalposition of the rotating part of fluid motor 38. Altemately, control 30may include means for sensing the fluid level in tanks 20 and 22 andswitching the tank which is being emptied whenever the fluid in a tankis detected below a certain predetermined level.

Assuming for the purposes of describing the operation of the embodimentof FIG. ll that control 30 has shifted valve 28 to a position such thatthe vapor pressure generated by boiler 26 is transmitted into tank 22 asdepicted, then that vapor pressure pushing the fluid in tank 22 causesworking fluid to exit from the bottom of tank 22 and to flow throughmotor 38 via one way check valve 32. Valve 32, as well as the othercheck valves in this and the other embodiments set forth below, permitfluid flow in one direction but prevent it in the other. These valvesmay be of any suitable type and are well known in the art. After passagethrough motor 38, the moving fluid passes through check valve 34 andenters tank 20. The difierential between the pressure of the fluidexiting from tank 22 and the fluid exiting from motor 38 prevents fluidfrom flowing back through check valves 36 and 38. An exhaust valve 40,which also is shown under the control of apparatus 30, is vented to theatmosphere during this time so that the fluid can freely enter chamber20. Valve 42 at the same time is closed to prevent the loss of the vaporpressure generated by the flow of vapor into tank 22 via valve 28.

The cyclic venting of tanks 20 and 22 to the atmosphere results in agradual reduction in the quantity of working fluid in the system.Reservoir 24 provides some makeup fluid since some of the vapor directedinto the tanks condenses therein and is thus added to the supply ofworking fluid. However, it may be desirable to provide some suitablearrangement for automatically or otherwise replenishing the workingfluid from time to time.

When tank 22 has been depleted or substantially depleted, controlmechanism 30 shifts the position of valve 28 so that the vapor pressuregenerated by boiler 26 is now directed into tank 20 and begins to forcethe fluid which has refilled it out of tank 20 and through fluid motor38 via check valve 36. At the same time, exhaust valve 40 is closed andvalve 42 opened by apparatus 30 so that the fluid now flowing throughmotor 38 via check valve 36 returns to tank 32 via check valve 39. Openvalve 42 permits the vapor pressure in chamber 22 to escape to theatmosphere so that tank 22 can refill.

A portion of the fluid flowing out of one or the other of the tanks 20or 22 also returns to reservoir 24 via valve 46 which may be controlledby apparatus 30 or may be manually or otherwise adjusted to provide asuitable flow of liquid into reservoir 24 for vaporization within boiler26. As mentioned above, while water is one suitable material whichexists in the vapor and gaseous phase and can be suitably used in thisarrangement, any other suitable fluid which can be satisfactorilyconverted from its liquid to its vapor phase can be employed.

Reference is now made to FIG. 2 which shows another embodiment of theinvention of this application. In this arrangement, the fluid motor 50is an AC hydrostatic motor which is capable of converting reciprocatingmotion into continuous shaft rotation, e.g., by means of a reciprocatingor swashplate motor. Such AC motors are well known in the art, and nofurther discussion of them is necessary. This embodiment of theinvention operates in the same fashion as the embodiment illustrated inFIG. 1 as discussed above with two tanks 52 and 54 alternately filledand emptied of the working fluid by means of vapor generated withinboiler 54 and alternately directed to tanks 52 and 54 by master valve 56which is under the control of a suitable control mechanism 58. Areservoir 60 is provided in the system and a valve 62 connects reservoir60 to the fluid in the two tanks for providing additional fluid forvaporization in boiler 54. Boiler or vapor generator 54 produces cyclicpressure at N times the hydraulic motor 50 shaft rotation frequency, Nbeing any suitable integer.

Reference is now made to FIG. 3 which depicts one suitable arrangementfor injecting fluid into a boiler or similar device, such as boiler 26depicted in FIG. 1, for conversion into a vapor phase such as steam. Thefluid thus injected is preferably divided into droplets which are assmall as possible to minimize the time required for vaporization. In theembodiment of FIG. 3, fluid enters vessel 70 through a conventionalinlet valve 72. Vessel 70 is constructed or associated with piezoelectric, magnetic restrictive, or solenoid driven material or structureso that the volume of vessel 70 is cyclically changed due to theharmonic residence of its elastic walls. Thus, the fluid which entersvessel 70 through inlet check valve 72 is cyclically injected intoboiler 74 for conversion from a liquid to gaseous phase. This injectiontechnique also I finely divides the injected droplets. In fact, inletvalve 72 may not be required in operation because water is injected intothe boiler steam generator 74 at such high rate to make backflow throughthe normally small orifices which will preferably be employed anegligible problem.

FIG. 4 illustrates another arrangement similar to that of FIG. 1 wherebythe fluid which is converted into vapor is derived directly from thevessels themselves. In this arrangement, fluid lines 76 and 78 areconnected to vessels 80 and 82 as shown. Valves 86 and 88 connect lines76 and 78, respectively, to a conventional boiler or other steamgenerator 90 which converts the received fluid from its liquid to itsgaseous phase. Master valve 92 directs the fluid to tanks 80 and 82alternately as in the embodiment of FIG. 1, and the fluid forced fromone tank by vapor pressure flows through actuator or fluid motor 94 andrefills the other tank in the same manner as in FIG. 1. Valves 86 and 88are operated by control mechanism which also controls master valve 92 sothat fluid is drawn from the tank which is refilling to provide fluid tobe vaporized to provide the pressure which imparts motion to the workingfluid. As in the other embodiments, vapor pressure in the tank beingrefilled is vented to the atmosphere through valves 102 and 104. Valves86 and 88 are cyclically opened to cause flow into boiler 90. The heatavailable from the walls of boiler 90 preferably converts the liquid tovapor. Preferably the period during which water flows into boiler 90 isrelated to the speed of sound in the vapor compared to its speed in theliquid and upon the geometrical proximities of valves and reservoirs.

FIG. 5 illustrates another embodiment of the invention similar to thatof FIG. 1 in which a hydrostatic resonant coupled acoustic pump isemployed to draw liquid from the drive system to be converted into vaporwithin boiler 110. As in the arrangement of FIG. 1, tanks 112 and 114are alternately emptied and refilled with the working fluid by means ofvapor pressure which is generated in boiler and alternately directedinto the respective tanks by master valve 116 which is controlled by asuitable control 120.

Whenever additional working fluid, e.g., water, is required for boiler110, tuning fork 120 is set in motion by any suitable mechanism. Forexample, in this embodiment tuning fork 120 is shown connected to thehydrostatic motor 124 by some suitable linkage mechanism. The horn mayalso be driven by cams or strikers from the motor 124. Horn 122magnifies the acoustic excursion generated by fork 120 by the inverseratio of the steam chamber inlet area to the base area so that water ispushed from the region of tuning fork 120 through horn 122 and injectedinto boiler 110 as fine droplets.

FIG. 6 illustrates one particular reservoir which is believed to be ofparticular use in conjunction with a system such as depicted in FIGS.1-5 and in the other Figures discussed below. In this arrangement, thereturning hot water enters tank 126 and is kept from the walls thereofby a thin-walled steam quench 128 which is provided with a number ofholes which permit the returning hot water to exit therefrom. Quench 128thus prevents the return water from thermally shocking the reservoirtank walls and also allows the heat stored in that wall to generatesteam within the reservoir tank itself.

FIG. 7 illustrates yet another embodiment of the invention similarly tothe basic DC hydrostatic drive system shown in FIG. 1. In thisarrangement, as in the others, fluid from two vessels 130 and 132 isalternately forced through a fluidic motor 134 via suitable checkvalves. However, this particular arrangement differs from thoseillustrated above in that the fuel which is burned to generate the heatwhich is converted to mechanical energy is also employed as the workingfluid. The fuel, e.g., methane, is stored in a suitable reservoir 136and added to the system at point 138 where the working fluid exists fromfluidic motor 134. The working fluid which is also the fuel then returnsto the tank 130 or 132 which is being refilled through the associatedcheck valve.

Part of the liquid which flows out of the tank 130 or 132 which is beingdepleted is also diverted through either valve 140 or 142, which areboth controlled by the control mechanism 134, into either boiler or 152,respectively, where heat is added to cause the fuel to change from aliquid to a gaseous state and expand into the associated tank so as toforce the working fluid therein out its exit to drive fluid motor 138and refill the other tank. The gas in the tank which is being refilled,for example, tank 130, is also exhausted to a burner via either valve164 or 166. An oxidant from a suitable reservoir 168 is also supplied toburner 160 for combusting the gaseous fuel. Thus the liquid fuel servesas the working fluid and the vapor which must be exhausted from the tankbeing refilled then combusted to provide a compact heat source. Floatinghead barriers may be disposed in each of the vessels 130 and 132 toincrease heat transfer between the gas and fluid stages.

FIG. 8 illustrates yet another modification of the basic hydrostaticdrive system set forth in FIG. 1. In this arrangement, heat exchangefrom the vapor expanding within the reservoir tank to feed water on itsway to the boiler or vapor generators provides a simple regenerativesystem. Tanks 170 and 172 are filled with a suitable working fluid as inthe other embodiment, and this working fluid is alternately forced outof one of the tanks 170 and 172 through fluidic motor 174 to refill theother tank. Further, some of the fluid forced from tank 172 or 174 isdiverted into line 176, and from line 176, the working fluid thusdiverted flows through either coil 178 or 180 depending on which of thecheck valves 184 and 186 is open. Valves 184 and 186 are under thecontrol of a suitable control apparatus 190 as shown so that the fluidis normally permitted to flow only through the coil 178 or 180 which isin the tank being refilled. The fluid passing through coil 178 or 180absorbs heat from the working fluid in the surrounding tank and from thehot vapor in that tank as it is exhausted. Thus, the feed fluid enterseither boiler 200 or 202 at an elevated temperature, which reduces thequantity of heat necessary to convert the fluid from a liquid to a vaporphase before injection into tank 170 or 172.

FIG. 9 illustrates another embodiment of the invention which isregenerative in the sense that heat in the working fluid is employed, atleast in part, to generate the vapor pressure which forces that fluidfor one tank through the motor to refill the other tank. In thisembodiment, two tanks 210 and 212 are designed to be filled to a maximumlevel which is just below the porous heat storage bed 214 with a fluidwhich will change from liquid to vapor phase at a suitable temperature.When heat is added to one side of storage bed 214, for example, the sideassociated with tank 210, the added heat causes a conversion of some ofthe fluid in vessel 210 from its liquid to its vapor phase resulting ina volume expansion which force part of the remaining fluid out the exitof vessel 210 and through a fluidic motor 220 to refill tank 210. Whentank 210 has been emptied to a desired level, the procedure is reversedand heat is added to the portion of the porous heat storage bed 214associated with tank 212. Next the working fluid in tank 212 ispartially vaporized so that part of the remaining fluid is out the exitof tank 212 and through fluidic motor 220 into vessel 210.

Meanwhile in the tank that is being refilled with working fluid, bed 214is absorbing heat from the fluid entering that tank. This heat isretained in bed 214 until that tank has been refilled and additionalheat can thereafter be added to cause partial vaporization of the fluidin that tank. Thus, the system is regenerative in the sense that aportion of the heat which is imparted to the working fluid and notinitially used to generate mechanical output is thereafter removed fromthe fluid and reused to generate mechanical output.

FIG. 10 shows yet another embodiment of the invention in which heat isexchanged in the system in a manner similar to an Ericson cycle. In thisarrangement, heat is generated, for

example, by burning methane or some other suitable fuel in.

burner 218, and then conducted into the vessel through coils 220 and222. Suitable valves may be provided for switching the flow of theexhaust gases and the heat to the respective tanks for cyclicallyemptying and refilling tanks 224 and 226. The fluid reentering either ofthe tanks also passes through a coil 228 or 230 before being emptiedinto vessel 226 or 224, respectively, so that the heat which exists inthe fluid which is leaving the tank on its way through motor 232 is inpart given back to the water which is returning to the vessel.Similarly, coils 242 and 244 are provided to at least partially cool thefluid exiting from motor 232.

FIG. 11 shows yet another embodiment of the invention whereby the heatimparted to the working fluid which would be otherwise lost is in partsaved and used to generate a mechanical output. In this embodiment, twotanks 240 242 are alternately filled and emptied with working fluidwhich passes through conventional fluid motor 244. Fuel such askerosene, natural gas, powdered coal or LP gas from a suitable source246 is combined with a suitable oxidant and combusted in a suitableburner 248 after passage through a valve 250 which may be manually orautomatically adjusted to permit flow of a desired amount of fuel. Heatfrom the burner 248 is employed to convert the working fluid injectedinto boilers 252 and 254 into vapor, in which state it is directed intotanks 7 240 and 242, respectively. Suitable valve means may be providedin boilers 252 and 254 if necessary or desirable.

A portion of the fluid exiting from the tank 240 and 242 being emptiedis drawn through either coil 260 or 262 into boiler 252 or 254,respectively. Valves 266 and 268 control the flow of fluid into coils260 and 262 and these valves are controlled in turn by a suitablecontrol apparatus 270 which insures that fluid will enter only thatboiler which is supplying vapor to the tank which is being emptied.Thus, if fluid is to be forced out of tank 240 by the addition of vaporto the top thereof, then valve 268 will be open and valve 266 closed sothat the fluid which passes valve 268 will pass through coil 262 and beinjected by a suitable injector into boiler 254. As the working fluidpasses through coil 262, heat is imparted to it by the burner 248 topreheat the fluid so that it arrives at the boiler at an elevatedtemperature, thus considerably increasing the amount of vapor that canbe injected into the tanks 240 and 242 within any given period of time.

Further, water or other fluid existing from the tank being emptiedpasses through heat exhanger 270 or 272 before passage through fluidmotor 244. These heat exchangers reduce the temperature of the workingfluid on its way to motor 244 and thereby decrease the possibility ofdamage to the fluid motor because of exposure to overheated fluid. Theheat in the fluid which enters heat exchanger 272 from the tank 240 or242 being emptied is in part transferred to the fluid which is leavingmotor 244 and is being returned to the tank 240 or 242 which is beingrefilled so that this heat raises the temperature of the fluid in thetank being refilled.

Reference is now made to FIG. 12 which shows another embodiment of theengine whereby water derived as a byproduct of hydrocarbon or other fuelcombustion is employed as a makeup supply for the working fluid of thesystem and further as means of rejecting into the atmosphere heat whichis not converted into useful mechanical output. This heat transfermanagement technique significantly simplifies the apparatus required forconverting chemical potential energy into shaft work and increases theefficiency compared to Otto or Diesel cycle processes.

Hydrocarbon fuels yield carbon monoxide and water when burned tocompletion in oxygen or oxygembearing atmospheres. The amount of waterproduced compared to the amount of carbon monoxide produced depends uponthe hydrogen to carbon ratio of the fuel being burned. In common liquidpetroleum fuels, the amount of water produced is ap proximately equal tothe amount of fuel burned. In liquefied petroleum gas fuels (butane,propane, methane, etc.) combustion products tend to an even greaterextent to be water. vaporization of water at a fixed pressure fixes theboil off temperature. At sea level the temperature for boil off is about212 F. and, at lower atmospheric pressure, the boil off temperature iscorrespondingly lower. The embodiment of the invention as illustrated inFIG. 12 uses this byproduct of hydrogenous fuel combustion as a makeupworking fluid supply.

In this embodiment, as in the other embodiments, two reservoir tanks 276and 278 are alternately discharged and refilled with working fluid whichflows from one tank to the other through fluid motor 280, thus,converting the pressure of the working fluid and the kinetic energyembodied in the flow of that fluid into useful output shaft power. Theflow of the working fluid is also cyclically directed via valves 262 and284 into the boilers 286 and 288 which provide the vapor pressure forforcing the working fluid cyclially from tanks 278 and 280. Fuel from asuitable source 300 is directed via valve 302 into boilers 286 and 288,respectively. Valve 302 may be under the control of a suitable mechanismsuch as control apparatus 304 which controls valves 282 and 284 as. wellas valves 306 and 308 in the same fashion as discussed above.

In contrast to the embodiment illustrated in FIG. 11, the fuel derivedfrom source 300 is combusted within boilers 286 or 288 which alternatelymay be any other type of combustion device suitable for combusting thefuel and directing the combined vapor and exhaust gases therefrom. Theexhaust gases of combustion together with the water or other vaporproduced from the working fluid are alternately passed into tanks 276and 278 to force the fluid therein to flow out the exit and pass throughthe fluid motor 280. In this fashion, the water vapor which is derivedfrom the burning of the hydrocarbon fuel and thus added to the system atleast in part replaces the vapor which is exhausted to the atmosphere bythe alternate opening of valves 310 and 312 during alternate refillingof tanks 276 and 278.

A portion of the fluid existing from motor 280 also passes throughvalves 306 and 308 which are under control of apparatus 304 and enterthe evaporator-radiator devices 320 and 322. These devices arepreferably provided with an open top or are otherwise accessible to theatmosphere so that the fluid that enters these devices evaporates to theatmosphere taking with it heat imparted to the evaporating fluid by theworking fluid which passes through coils 324 and 326 on its way to fluidmotor 280. Part of the heat imparted to the fluid in evaporators 320 and322 is also transmitted to the fluid returning to tanks 276 and 278 viacoils 330 and 332. Thus, part of the heat of the working fluid in tanks276 and 278 is employed to preheat the fluid returning to the tanksafter passing through motor 280 and part is vented to the atmosphere sothat the fluid which is passed through motor 280 is at a temperaturewhich will not damage the motor.

As in the other embodiments, the working fluid in this embodiment may bewater or may be more sophisticated solutions, e.g., mixtures of waterand other compounds which might, for example, prevent freezing, increaselubricity, increase or decrease heat transfer, or aid or retardabsorption and retention of combustion gases. Conversely, the workingfluid may contain a less dense compound or particle which floats uponits surface, thus providing insulation between the combustion gases andworking fluid during the period that the pressure is being transmittedin from the hot gases to the working fluid in the reservoir. Compoundsadded to the working fluid may be separated from vaporizable orcombustible portions of the working fluid prior to admission to thegenerator-combustor sections such as boilers 286 and 288.

By utilization of common and inexpensive steels, ceramics, bearings,valves and other hardware, the embodiment of the invention illustratedin FIG. 12, as well as the embodiments of the other figures, may bedesigned to operate at temperatures of, for example, 2,000 F. and 6,000lbs. per square inch at the inlet of the tank receiving the vaporthrough 160 F. or lower by use of heat-dams, insulation, and otherarrangements such as flow deflectors and surface coatings. Conversely,the upper portion of the reservoir walls may be maintained attemperatures exceeding l,200 F. if desired, thus allowing heat input andstorage previous to steam generation by conduction of heat into thefluid at the time during the filling of the reservoir tank that thefluid level reaches the high wall temperature level.

The basic versatility of the embodiment of FIG. 12 is furtherillustrated by the potential of using more than two fluid reservoirs.Manufacture of 100 horsepower modules consisting of two reservoirs andone motor actuator allows engine units of 200 hp., 400 hp., 600 hp., and1,000 hp., or more, to be assembled simply by joining the output shaftsof each motor to a common output shaft. Such an output shaft would onlyhave the minimum fabrication requirement of being attachable per theapplication function and would not involve the various sophisticationscharacteristic of internal combustion engine crankshafts. Similarlymultiple reservoir modules may be hydraulically connected to a singlemotor.

The vast variety of hydrostatic, hydraulic, and hydrodynamic actuatorsfurther exemplifies particularly the versatility of the embodiment ofFIG. 12 in various applications only being transmissions, angle drives,universal joints, and differentials. The probability of costly failureis inherently reduced in the embodiment. Fig. 12, as well as the otherembodiments, compares favorably to conventional internal combustionreciprocating engines by the reduced number of workings parts, thereduced metal to metal relative motion, and the reduced gyratory forcesinvolved. The ability to achieve high horsepower to weight ratios athigh efficiencies, particularly when materials selections typical toaircraft turbines are made, makes the engine shown in FIG. 12 preferableto turbines for propeller driven aircraft.

Reference is now made to FIG. 13 which shows another embodiment of theinvention which is somewhat similar to the conventional Stirling cycleengine. The Stirling cycle distinguishes itself primarily as oneemploying regeneration techniques in which heat is transferred from theworking fluid into a thermal reservoir as a working fluid begins itsexpansion. After mechanical output has been generated, the stored heatis readded to the cooled working fluid as it is being reheated to themaximum temperature of the cycle.

The embodiment of the invention illustrated in FIG. 13 is similar inthat it is regenerative, but this embodiment also employs advantageousaspects of both the liquid and gas phases in the process of convertingheat into mechanical work. In the embodiment illustrated in FIG. 13,heat, for example, produced by combustion of hydrocarbon or other fuels,nuclear fission, or fusion is transferred into vapor phases of theworking fluid at heat source 350 which may be, for example, a boilersuch as in the other embodiments.

As in the other embodiments, heat from source 350 is employed to convertworking fluid from a liquid to a gaseous phase and to direct the vaporpressure thus generated alternately into tanks 352 and 354 so thatworking fluid is forced out of one of the tanks and through fluidicmotor 356 to refill the other tank. A portion of the working fluid whichis forced out of each of the tanks is also employed to provide liquidfor conversion to a gaseous phase. However, in this embodiment, fluid onits way to a vapor generator such as a boiler passes through a heatingcoil in the tank being refilled so as to absorb as much of the heat aspossible from the fluid entering that tank and also to absorb as muchheat as possible from an extended heat transfer surface which is mountedadjacent to the coil through which the fluid passes. For example, aportion of the fluid exiting from tank 352 passes through valve 360 andcoil 362 which is mounted in tank 354 as shown. During the time thattank 354 is refilling, working fluid on its way to boiler 366 passesthrough tank 354 via coil 362. The fluid returning to tank 354 frommotor 356 passes through negative heat rejection coil 364 and the fluidreturning to tank 352 through negative heat rejection coil 365.

Further, an extended heat transfer surface comprising coil 367 withintank 354 is mounted adjacent coil 362. Coil 367 absorbs heat from theworking fluid reentering tank 354 and also absorbs heat from the exhaustgases generated by source 350 which are exhausted to the atmosphere viacoil 367 as well as coil 370. The heated fluid existing from coil 362 isinjected into boiler 366 where it is converted into its vapor phase andthat vapor then transmitted to tank 352 to force the working fluidtherein out its exit and through motor 356. Coils 368 and 370 withintank 352 operate similarly when that tank is being refilled, and tank354 is being emptied. As shown, coils 362 and 368, which each preferablycomprise a hollow coil, are connected to an exhaust 372 so that, forexample, the hot combustion gases are transmitted through coils 366 and368 so that the heat of the combustion gases can, at least in part, beimparted to the working fluid which is to be vaporized and eventuallyemployed to generate a mechanical output. Nuclear loop transfers, ofcourse, would not need an exhaust but preferably employ a similarcircuit to optimize the efficiency of energy conversion.

Reference is now made to FIG. 14 which shows yet another embodiment ofthe invention. In this arrangement, two or served today by complexmechanisms involving clutches, more working fluids are employed topermit extension of the thermal gradiant to higher and lowertemperatures than allowed by a single working fluid. This arrangementoffers considerable advantages from the standpoint of thermodynamics. Inthis embodiment, as in the embodiment of FIG. 11, fuel from a suitablesource 400 is burned by a suitable burner 402 adjacent conventionalboilers 406 and 408. Vapor thus generated is alternately directed intoreservoir tanks 410 and 412, one of which is continually emptying andrefilling the other through fluidic motor 414 and thus generating acontinuous and useful mechanical shaft output.

However, fluid issuing from either of the tanks 410 or 412 passesthrough a heat exchanging coil 414 or 416 on its path through motor 414,thus imparting heat to the fluid in lines 420 and 422 respectively whichwill normally contain working fluid having a different critical pointthan the working fluid in tanks 410 and 412. The heat thus impartedcauses the fluid in lines 420 and 422 to change from its liquid to itsvapor phase and the resulting expansion of the working fluid causes thefluid in tanks 424 and 426 alternately to be forced through a secondfluid motor 426 which may be in parallel with the first motor forcombining the mechanical shaft output.

A number of combinations of working fluids can be employed in thisarrangement. A few examples are mercury and water, mercury andpotassium-sodium eutectic, water and freon, water and silicone fluids,freon and liquefied gases and many others. A simple extension of theillustrated system permits the development of engines which use three orfour or more working fluids.

Reference is now made to FIG. which shows yet another embodiment of theinvention in which two hydrostatic systems, each having two tanks areemployed to operate a single shaft with two motors 402 and 404 connectedin parallel. It should be apparent that any number of systems such asillustrated above can connected together to generate any desired poweroutput.

FIG. 16 shows yet another embodiment of the invention wherein elasticdiaphragms 410 and 412 are connected between two working fluids. Thediaphragms separate each of the two tanks 416 and 418 into an upper andlower compartment. The fluid in the upper compartment, for example, thefluid in the upper part of tank 410 can be expanded for any suitablemeans, for example, by heating in boiler 420 with the result that thedownward pressure exerted by elastic diaphragm 412 forces the fluid inthe lower portion of tank 418 out of its exit and through hydrostaticmotor 420 thus deriving a mechanical output. The fluid thus forced fromtank 412 then refills the bottom portion of tank 410 which then forcesthe fluid out of the upper portion and thereof and into the upperportion of tank 410 via valve 422. The process is then reversed with thefluid in the lower portion of tank 410 being forced out by the fluidexpanded by boiler 426 and directed into the upper portion of tank 410.Similarly pistons, bellows, and floating particles may be used toseparate the fluids.

Reference is now made to FIG. 17 which shows a hydrostatic drive systememploying only a single reservoir tank 424. This embodiment which couldbe used, for example, in a rocket system for travel in outer spaceemploys the heat generated by the fuel which is combusted to supply therocket thrust to impart motion to the fuel which then serves as theworking fluid for conventional hydrostatic or other similar motor 426.The heat generated in combustion chamber 428 which is normally wasted isemployed to convert the fuel fluid from a liquid to a gaseous state inpressure source 430 so that the pressure thus generated forces the fuelfluid in tank 424 out its exit and through motor 426 to be burned incombustion chamber 420. A cooling arrangement 432 can be disposedadjacent the tank 424 for condensing some of the vapor added to tank 424into a liquid which can then be used as the working fluid and combustedafter passage through motor 426.

FIG. 10 shows a modification of the embodiment of FIG. 7 whereby theheat generated by combusting the working fluid in a combustion chamber440, for example, to generate thrust to propel a rocket or other vehicleis employed by a heater 442 which has coils disposed about reservoirtank 444 which is filled with a suitable fuel fluid. The heat added tothe fluid in tank 444 by heater 442 causes a portion of it to beconverted into a vapor state and expand, thus forcing part of theworking fluid in chamber 444 out past valve 446 and through fluid motor448 to combustion chamber 440 where it is burned. Thus, the waste heatfrom the combustion is employed to generate the mechanical output whichcan be employed in the device for any purpose desired.

The above discussed embodiments of the invention can of course besatisfactorily employed in a number of applications. These include, butare not limited to:

a. Air heating and cooling,

b. Lawn mowers,

c. Motor-generator units,

d. Garden Tractors,

e. Sump pumps,

f. Garbage Disposal and Compaction,

g. Irrigation pumps,

h. Electrical Power Generation i. Compressor Stations j. Oil and GasDrill Drilling and Pumping k. Elevators and Lifts l. Conveyors m. OreCrushers and Pulverizers 11. Grain mills 0. Scrap Shredders andCompactors p. Automobile q. Rail Cars r. Bus and Train s. Truck andTractors t. Other Farm Equipment u. Highway construction equipment v.Pleasure and Commercial Boats w. Aircraft The following table representsa few resultant engine horsepowers and weights based upon the use offired boiler rated steels and conventional hydrostatic motors as derivedfrom computer modeling studies.

The use of titanium alloys, composites, and coatings will permitconsiderable improvement in the weight to power ratios of the Table.However, for most applications the Table ratios will be sufficient.

Many changes and modifications in the above discussed embodiments of theinvention can of course be made without departing from the scope of theinvention. Accordingly, that scope is intended to be limited only by thescope of the appended claims.

What is claimed is:

1. An energy conversion system comprising:

first means for containing a working fluid, second means for containinga working fluid, motor means operatively communicating with said workingfluid in said first and second containing means for receiving saidworking fluid so that said working fluid flows into and out of at leasta portion of said motor means so as to generate a mechanical motion,

means for alternately supplying a given fluid in a vapor phase to saidfirst means at a pressure such that said working fluid is forced fromsaid first means, into and out of said portion of said motor means andinto said second means and to said second means at a pressure such thatsaid working fluid is forced from said second means, into and out ofsaid portion of said motor means and into said first means,

means for receiving said fluid in a liquid phase and for heating saidfluid in said liquid phase to convert it to said given fluid in saidvapor phase, and

means for receiving a portion of said working fluid forced from saidfirst and second means and injecting said portion in fine droplets intosaid receiving and heating means.

2. A system as in claim 1 wherein said motor means is a DC fluid motor.

3. A system as in claim 1 wherein said motor means is an AC fluid motor.

4. A system as in claim 1 further including first check valve meansconnecting said first means to the entrance of said portion of saidmotor means for permitting fluid to flow from said first means towardsaid motor means and for preventing flow from said motor means towardsaid first means, second check valve means connecting said second meansto the entrance of said portion of said motor means for permitting fluidto flow from said second means to said motor means and for preventingflow from said motor means toward said second means, third check valvemeans connecting the exit of said portion of said motor means to saidfirst means for permitting fluid to flow from said exit to said firstmeans when said given fluid in said vapor phase is being supplied tosaid second means and for preventing flow from said first means to saidexit and fourth check valve means connecting said exit to said secondmeans for permitting fluid to flow from said exit to said second meanswhen said given fluid in said vapor phase is being supplied to saidfirst means and for preventing flow from said second means to said exit.1

5. A system as in claim I wherein said first and second means are tanksand said receiving and heating means includes means for combusting afuel and means for supplying said fuel to said combusting means.

6. A system as in claim 1 wherein said receiving and injecting meansincludes a vessel having walls adapted for harmonic resonance, an inletfor receiving said portion of said working fluid and an outlet connectedto said receiving and heating means and means for harmonicallyresonating said walls to inject said fluid into said receiving andheating means as fine droplets.

7. A system as in claim 1 wherein said receiving and injecting meansincludes a liquid horn having a large inlet for receiving said portionof said working fluid and a small outlet connected to said receiving andheating means and tuning fork means mounted adjacent said inlet forcausing said horn to inject said droplets into said receiving andheating means.

8. A system as in claim 1 wherein said first and second means are eachreservoir tanks and wherein each said tank includes a thin walled quenchtube having a plurality of apertures and mounted within that tank forreceiving said working forced into said tanks so as to prevent thermalshock to the walls of that tank.

9. A system as in claim 1 further including means for venting said firstmeans to the atmosphere while said supplying means is supplying saidgiven fluid in said vapor phase to said second means and for ventingsaid second means to the atmosphere while said supplying means issupplying said given fluid in said vapor phase to said first means.

1. An energy conversion system comprising: first means for containing aworking fluid, second means for containing a working fluid, motor meansoperatively communicating with said working fluid in said first andsecond containing means for receiving said working fluid so that saidworking fluid flows into and out of at least a portion of said motormeans so as to generate a mechanical motion, means for alternatelysupplying a gIven fluid in a vapor phase to said first means at apressure such that said working fluid is forced from said first means,into and out of said portion of said motor means and into said secondmeans and to said second means at a pressure such that said workingfluid is forced from said second means, into and out of said portion ofsaid motor means and into said first means, means for receiving saidfluid in a liquid phase and for heating said fluid in said liquid phaseto convert it to said given fluid in said vapor phase, and means forreceiving a portion of said working fluid forced from said first andsecond means and injecting said portion in fine droplets into saidreceiving and heating means.
 2. A system as in claim 1 wherein saidmotor means is a DC fluid motor.
 3. A system as in claim 1 wherein saidmotor means is an AC fluid motor.
 4. A system as in claim 1 furtherincluding first check valve means connecting said first means to theentrance of said portion of said motor means for permitting fluid toflow from said first means toward said motor means and for preventingflow from said motor means toward said first means, second check valvemeans connecting said second means to the entrance of said portion ofsaid motor means for permitting fluid to flow from said second means tosaid motor means and for preventing flow from said motor means towardsaid second means, third check valve means connecting the exit of saidportion of said motor means to said first means for permitting fluid toflow from said exit to said first means when said given fluid in saidvapor phase is being supplied to said second means and for preventingflow from said first means to said exit and fourth check valve meansconnecting said exit to said second means for permitting fluid to flowfrom said exit to said second means when said given fluid in said vaporphase is being supplied to said first means and for preventing flow fromsaid second means to said exit.
 5. A system as in claim 1 wherein saidfirst and second means are tanks and said receiving and heating meansincludes means for combusting a fuel and means for supplying said fuelto said combusting means.
 6. A system as in claim 1 wherein saidreceiving and injecting means includes a vessel having walls adapted forharmonic resonance, an inlet for receiving said portion of said workingfluid and an outlet connected to said receiving and heating means andmeans for harmonically resonating said walls to inject said fluid intosaid receiving and heating means as fine droplets.
 7. A system as inclaim 1 wherein said receiving and injecting means includes a liquidhorn having a large inlet for receiving said portion of said workingfluid and a small outlet connected to said receiving and heating meansand tuning fork means mounted adjacent said inlet for causing said hornto inject said droplets into said receiving and heating means.
 8. Asystem as in claim 1 wherein said first and second means are eachreservoir tanks and wherein each said tank includes a thin walled quenchtube having a plurality of apertures and mounted within that tank forreceiving said working forced into said tanks so as to prevent thermalshock to the walls of that tank.
 9. A system as in claim 1 furtherincluding means for venting said first means to the atmosphere whilesaid supplying means is supplying said given fluid in said vapor phaseto said second means and for venting said second means to the atmospherewhile said supplying means is supplying said given fluid in said vaporphase to said first means.